Project · Distortion
Klon™ Centaur™ Overdrive Replica
This is a replica of the Klon™ Centaur™, the transparent overdrive that sells for thousands used; ours sounds very close to a silver Centaur™ and costs $61 as a complete kit with every part included. It keeps the original's germanium clipping diodes, 7660 charge pump and dual-gang gain pot, and the free schematic and wiring diagram are here whether you buy the kit or not.
The original Klon™ Centaur™ put out some of the best and most coveted overdrive sounds in the world! We encourage you to leave behind all the hype and forget about everything (good or bad) that you've heard about the pedal and treat this kit project as the overdrive that it is. This pedal (built from our kit) is, overall, the best overdrive that we've heard. Although we haven't had a chance to compare our unit with a real vintage Klon™ Centaur™, we believe they would sound very similar. This is not anywhere near the same price-range and hype-range as a real Klon™ Centaur™. So take it for what it is; a really good overdrive kit from General Guitar Gadgets at a reasonable price!
We have internet-researched the Klon™ Centaur™ extensively. Based on the information available, we believe that this is as close as it gets to being an accurate circuit replica of the "Silver" Klon™ Centaur™. We also spent some time comparing the control settings of our kit pedal with control settings of actual units seen on youTube videos to see if we were getting the same audio responses. We believe that we do get similar response and sounds. This is a great kit at a great price. Enjoy the Tone!
The story
About the circuit
Bill Finnegan built the first Klon™ Centaur™ in Boston in 1994 after several years of development with two MIT-trained engineers, and hand-assembled roughly 8,000 units before stopping in 2008. The goal was an overdrive that made a good amp sound more like itself, not like a different pedal. Three design choices do most of the work: a charge pump that doubles the 9-volt supply to give the op-amps more headroom; a dual-gang gain pot that blends a clean path with a clipped path, so the dry signal is always present; and a pair of germanium diodes that clip the signal to ground after the gain stage, with the low threshold germanium gives. Most units were gold; a silver finish was offered alongside it. The "transparent overdrive" reputation and the used prices that followed both came later.
This project at GGG
For years we stayed away from the Klon™. JD's rule from the very beginning was not to clone boutique pedals still in production, and the Centaur™ was exactly that. When Finnegan stopped building them and the used prices went through the roof, the circuit became fair game, and in 2014 we put out our replica of the silver unit: the charge pump, the dual-gang gain control, the germanium diodes and the original's buffered bypass are all there. If you would rather have true bypass, the modification sheet and layout are in the files above. The board is sized for a 1590BB. We have tuned the parts list once since, and added the true-bypass option when enough builders asked for it. Thousands of these have been built from this page, and it is consistently our best-reviewed kit.
Project files
Everything you need to build it
Klon™ Centaur™ Replica Ready-For-Transfer Printed Circuit Board Layout For use only if you are a complete DIY person who wants to etch and drill your own PCB. Otherwise, we recommend you ignore this PCB mask and buy the Ready-to-Solder Printed Circuit Board or Complete Kit from the links below.
Schematic
Schematic
Parts layout
Parts Layout / Wiring Diagram
What you will need
Bill of Materials
Version 2017September17 · Copyright 2014 JD Sleep · Permission refused for posting/serving this file from any site other than www.generalguitargadgets.com · Trademarks are property of their owners
Resistors
| Resistor ID | Value | 3-band Marking | 4-band Marking |
|---|---|---|---|
| R1 | 10k | brown-black-orange | brown-black-black-red |
| R2 | 1M | brown-black-green | brown-black-black-yellow |
| R3 | 100k | brown-black-yellow | brown-black-black-orange |
| R4 | 560 ohm | green-blue-brown | green-blue-black-black |
| R5 | 5k1 (5.1k) | green-brown-red | green-brown-black-brown |
| R6 | 10k | brown-black-orange | brown-black-black-red |
| R7 | 1k5 (1.5k) | brown-green-red | brown-green-black-brown |
| R8 | 1k5 (1.5k) | brown-green-red | brown-green-black-brown |
| R9 | 1k | brown-black-red | brown-black-black-brown |
| R10 | 2k | red-black-red | red-black-black-brown |
| R11 | 15k | brown-green-orange | brown-green-black-red |
| R12 | 422k | yellow-red-red-orange | |
| R13 | 1k | brown-black-red | brown-black-black-brown |
| R14 | 1k | brown-black-red | brown-black-black-brown |
| R15 | 22k | red-red-orange | red-red-black-red |
| R16 | 47k | yellow-violet-orange | yellow-violet-black-red |
| R17 | 27k | red-violet-orange | red-violet-black-red |
| R18 | 12k | brown-red-orange | brown-red-black-red |
| R19 | 15k | brown-green-orange | brown-green-black-red |
| R20 | 392k | orange-white-red-orange | |
| R21 | 1k8 (1.8k) | brown-gray-red | brown-gray-black-brown |
| R22 | 100k | brown-black-yellow | brown-black-black-orange |
| R23 | 4k7 (4.7k) | yellow-violet-red | yellow-violet-black-brown |
| R24 | 100k | brown-black-yellow | brown-black-black-orange |
| R25 | 560 ohm | green-blue-brown | green-blue-black-black |
| R26 | 68k | blue-gray-orange | blue-gray-black-red |
| R27 | 68k | blue-gray-orange | blue-gray-black-red |
| R28 | 100k | brown-black-yellow | brown-black-black-orange |
| R29 | 27k | red-violet-orange | red-violet-black-red |
| R30 | 27k | red-violet-orange | red-violet-black-red |
Capacitors
| Capacitor ID | Value | Type | Possible Marking |
|---|---|---|---|
| C1 | 0.1µF | Film or Ceramic | 104 or µ1k... |
| C2 | 4.7µF | Aluminum Electrolytic | 4.7µF |
| C3 | 0.1µF | Film or Ceramic | 104 or µ1k... |
| C4 | 0.068µF | Film or Ceramic | 683 |
| C5 | 0.068µF | Film or Ceramic | 683 |
| C6 | 0.39µF | Film or Ceramic | 394 |
| C7 | 0.082µF | Film or Ceramic | 823 |
| C8 | 390pF | Film or Ceramic | 391 |
| C9 | 1µF | Aluminum Electrolytic | 1µF |
| C10 | 1µF | Aluminum Electrolytic | 1µF |
| C11 | 0.0022µF | Film or Ceramic | 222 or .0022... |
| C12 | 0.027µF | Film or Ceramic | 273 |
| C13 | 820pF | Film or Ceramic | 821 |
| C14 | 0.0039µF | Film or Ceramic | 392 |
| C15 | 4.7µF | Aluminum Electrolytic | 4.7µF |
| C16 | 1µF | Aluminum Electrolytic | 1µF |
| C17 | 47µF | Aluminum Electrolytic | 47µF |
| C18 | 47µF | Aluminum Electrolytic | 47µF |
| C19 | 1µF | Aluminum Electrolytic | 1µF |
| C20 | 1µF | Aluminum Electrolytic | 1µF |
| C21 | 1µF | Aluminum Electrolytic | 1µF |
| C22 | 1µF | Aluminum Electrolytic | 1µF |
Potentiometers
| Part ID | Value | Type |
|---|---|---|
| R31 – Gain Control | 100k | Linear Taper Dual-Gang |
| R32 – Treble Control | 10k | Linear |
| R33 – Output Control | 10k | Linear |
Other
| Part ID | Part Name |
|---|---|
| D1 | LED (for indicator) |
| D2 | 1N34A (or other Germanium diode) |
| D3 | 1N34A (or other Germanium diode) |
| D4 | 1N4742 |
| D5 | 1N4001 |
| D6 | 1N4001 |
| IC1 | TL072 |
| IC2 | TL072 |
| IC3 | 7660 Charge Pump |
| J1 | Stereo quarter-inch jack |
| J2 | Mono quarter-inch jack |
| J3 | DC Jack |
| B1 | 9 volt battery (not included in the Kit) |
| Sw1 | Heavy Duty DPDT or 3PDT foot switch 9v battery snap, Printed Circuit Board, 24 gauge stranded wire, Enclosure, Knobs |
How to build it
Instructions
Version 2018September05 · Copyright 2014, 2018 JD Sleep · Permission refused for posting/serving this file from any site other than www.generalguitargadgets.com · Trademarks are property of their owners
This is a replica of the famous Klon™ Centaur™ Sometimes referred to as KC in these documents. The original Klon™ Centaurs put out some of the best and most coveted overdrive sounds in the world! Use the project documents provided, starting with the General Build Instructions. There is some component off-board wiring in this project. This may test your soldertacking skills and therefore this is not necessarily a beginner builder's kit. Use the layout diagram and the photos below to help place those off-board parts which are the four resistors (R14, R26, R27, R28). Note that we used a 3PDT foot switch, when only a DPDT foot switch is required. We did this because we don't stock DPDT foot switches and so that you could modify the pedal to true-bypass if you wish, using the typical true-bypass wiring arrangement that almost all the other kits use. True Bypass diagrams are also provided on the project page, although it’s not necessarily recommended.
Here's an inside view of the unit we built to show our construction details.
Here is a chart of voltages taken at the IC pins. This information can be used to help you find and fix problems if your Centaur™ doesn't work when you test it. The voltages are approximate, you may not get these exact readings, but they should be somewhat similar.
Component
Location
Voltage
9 volt power supply IC1
IC2
IC3
9.4v IC Pin 1
4.7v
IC Pin 2
4.7v
IC Pin 3
3.6v
IC Pin 4
0v
IC Pin 5
4.7v
IC Pin 6
4.7v
IC Pin 7
4.7v
IC Pin 8
9.4v
IC Pin 1
4.8v
IC Pin 2
4.7v
IC Pin 3
4.7v
IC Pin 4
-9.1v
IC Pin 5
4.7v
IC Pin 6
4.7v
IC Pin 7
4.6v
IC Pin 8
17.1v
IC Pin 1
9.4v
IC Pin 2
4.7v
IC Pin 3
0v
IC Pin 4
-4.5v
IC Pin 5
-9.1v
IC Pin 6
5.0v
IC Pin 7
7.4v
IC Pin 8
9.4v
Comments and questions are welcome and can be sent to
Questions
Frequently asked questions
Does it sound like a real Klon™?
It uses the same circuit, germanium diodes and 18-volt charge pump as the original, and builders compare it closely with a silver Centaur™. We have not had it side by side with a real unit, so judge it on its own sound.
Is this a beginner build?
No. It has about 60 parts, three ICs, a dual-gang pot and four resistors mounted off the board, so build a simpler kit first (the Fuzz Face™ or Stratoblaster™ are good starters).
Buffered or true bypass?
The kit is buffered like the original, which is part of the Klon™ sound. A true-bypass schematic and layout are included if you prefer it.
Which germanium diodes?
1N34A, included in the kit. Any small-signal germanium diode works; forward voltage affects the clipping character.
More about this project
Notes, sounds and related links
Ready to build? We have the kit.
Buy a Klon™ Centaur™ Replica Complete Kit. Includes all the parts and materials you need to build one, all for about the price you would pay for a PCB and parts.
Would you like a Ready to Solder Circuit Board for this project?